Signal lamp



Oct, 9, 1928. 1,686,822

S. L. LEBBY SIGNAL LAMP Filegl Aug. 30, 1923 2 Sheets-Sheet 1 6% his Lee 116 9 attorney Oct. 9, 1928. 1,686,822

5. 1.. LEBBY SIGNAL LAMP Filed Aug. so. 1925 2 Sheets-Sheet 2 Suva/Mic Patented Oct. 9, 1928.

UNITED STATES v 1,686,822 PATENT OFFICE.

sra'rns LEE LEBRY, or coRNINe, NEW YORK, ASSIGNOR TO CORNINGF GLASS WORKS,

or CORNING, NEW YORK, A CORPORATION on NEW YoRx.

SIGNAL LAMP.

Application filed August 30,1923. Serial No. 660,211.

This invention is an improvement in signal lamps or projectors and more particularly to focusing means therefor.

The invention aims to provide a focusing means of a simple and economical. nature which may be readily manipulated without requiring access to the interior of the lamp. The invention further aims to provide a construction which will afford extreme accuracy of adjustment, and by which accidental movement of the several parts of the lamp due to various causes will be prevented.

With these and other objects in view the invention includes the novel features of construction and arrangement and combination of parts, hereinafter described and particularly defined by the appended claims.

An embodiment of my invention is illustrated in the accompanying drawings in which r Fig. 1 is a vertical longitudinal section taken through a signal lamp incorporating the invention.

Fig. 2 is a vertical transverse section taken on the line 2-2, of Fig. 1;

Fig. 3 is a rear view, with the rear cover removed; I

Fig. 4 is a detail view ofa portion of the light-supporting means; i i

Fig. 5 is a perspectlve W 'W of thebracket Fig. 6 is a sectional view of the bracket and guide taken on the line 66 of Fig. 5. My invention is capable of embodiment in practically any known type of light projector employing an incandescent light source, but for convenience I have illustrated it in connection with a signal lamp, such as is mounted Y on semaphore poles of railway signal apparatus. y Y

In the drafwings the numeral 1 designates the lamp casing, having a reflector 2 mounted in its rear'by means of a screw connection 3,

and its open front provided with a coverglass 4. The cover-glass isretained in position by means of a front. plate 5 fastened to the front of the casing by screws 6. Interposed between the front face of-the. casing and the plate 5 is an annular disk 7 having an opening 8 therein of less diameter than the cover glass. This disk, which is held in position by tapered pins 9'driven through the front of the plate as shown, is in the nature of a focusingtarget, and substantially the, whole of the beam of projected light passes through the opening 8 thereof, v

and has its upper and outer curved face pos1- tioned in the socket 11 of the arm 10. The arm 10 is attached to the bracket 14 by a bolt 15 which is passed through the perforated socket 11, the opening 13 of the cup 12, and an opening 36 formed in the bracket 14,

as shown in Fig. 1. In this manner, the construction provides for unlversal movement of the casing with respect to a fixed support,

and as will be readily understood, the lam can be accurately adjusted to the desired position, and then positively retained in such position.

The lamp bulb, which is indicated by the numeral 16, is supported by a. socket 17 clamped to the upper end of a standard 18. The standard is formed by doubling a suitable length of stiff sheet metal upon itself to provide a fiat, thin central portion, and upper and'lower eyes 20 and 21, respectively, the upper eye 20 receiving the socket 17, while the lower eye 21 is fixed on a horizontally disposed rod 22 near one'end thereof. This end of the rod passes with a slight clearance through an opening 22 in the bracket 24.

The standard is slidably mounted in a guide formed by doubling the upper portion,

of the sheet metal from which the bracket is made, "upon itself, until the. walls 19 are brought into tapering relation toward-their free edges,.a channel 23 being'thus formed between the walls. The rear portion of the channel is occupied by the feed wires for the bulb. The edges of the walls 19 have a slidin fit against the standard. Thus the stand ard may slide within its own plane in the guide, and may be turned therein upon the .edges of the Walls 19, as fulcrums.

The outer end of the rod 22, which is threaded, as shown, projects throu h a large opening 25 formed in the rear of the casing, and then passes through a smaller 0 emng 26 in an arcuately shaped plate 27. A. t umbscrew 28, havin a flange 29, is threaded on the outer end of the rod, and is so dlsposed with respect to the plate, that when the parts are assembled as shown, the upper portion of the flange of the nut Will be on the inside of the plate, while the lower portion of the flange will be on the outside of the plate, and in this manner longitudinal movement of the nut with respect to the plate is prevented, when the nut is turned on the rod, while the rod will be moved longitudinally, as will be understood.

For the purpose of retaining the parts in proper position, and taking up lost motion, a coiled spring 30, having one of its ends connected'to the rod near the threaded'end thereof and its other end connected to the bracket 24, is provided. When the parts of the lamp bulb supporting structure are being adj usted,

the spring will serve as means for resiliently retaining the parts in adjusted position before being locked, and also for taking up any lost motion of the parts, and further serves to bind the nut 28 in adjusted position, thereby preventing accidental movement of the nut.

When the light bulb is being shifted so asto bring to proper focus, it is necessary to move i'ts supports with respect to the axis of the casing, so as to impart movement of the light sourceinfa plane perpendicular to the axis ,of the lamp, thus centering the light source ontlfe' axis, so for this purpose, the

plate 27-is"provided with a slot 31 that is cut into its upper end, as shown by Fig. 3, which allows vertical movement of the plate. A stud 32, which is threaded into the casing above the opening 25 has its shank passed through the slot 31, and carries a nut 32 thereon bearing" against the plate 27. vWhen the nut is loosened the plate can be shifted in any direction to properly center the light source. or outer end of the rod may be had by moving the plate vertically, this being allowed by the slot 31,'and transversemovement of the rear end of the rod may be had byrmoving the plate aboutthe stud, as a pivot.

To adjust the light source in accurate focal relation with the reflector, the nut 28 is turned in a proper direction to obtain the proper focal distance, i. e, such distance that a beam of such spread as to fill the opening 8 in the disk 7, is produced, by shifting the light source back or forth with respect to the re flector. The light source isthen accurately centered by loosening the nut 32 on the stud 32 and adjusting the plate 27, by swinging the rod 22 in the opening 22' as a ,pivot to move the light source transversely with respect to the axis of the projector, until it is on the axis, at which point the beam will be accurately directed through the opening '8. The parts are then looked in position by turning the nut 32 down on'the stud '32.

As heretofore stated, the plate 27 is arcuately shaped. This arcuately shaped plate Thus vertical movement of the rear.

fits againsta correspondingly arcuately or spherically shaped face-of the casing. The

center of curvature of the plate 27, and the ment which brings the light source to the position for directing the beam through the opening 8 in the disk 7, the light source will move in such a curve that the spread of the projected beam will not be disturbed, although its direction will be varied as the light source is moved. Hence, in adjusting the light source, the longitudinal adjustment which varies the spread of the beam is made by turning the nut 28 in the proper direction, and then the transverse or centering adjustment is made by moving the plate 27, but the centering adjustment which shifts the direction of the beam, does not disturb the first adjustment which controls the spread of the beam, by reason of the curved path which the light source traverses in making the centering .adj ustment.

For the purpose of preventing accidental or' unwarranted handling of the adjusting means, the lower portion of the rear of the casing is enclosed by a cover 33 which may be locked in position in any-desired manner, as by a pad-lock, as indicated by the numeral 34.

Having thus described the invention, whatis claimed is 1. The combination with a'projectorcasing and its light source, of means for supporting and focusing the light source comprising a standard carrying said source at its upper end, a rod on which the standard is carried, said rod having its outer end projecting through the casing, a guide bracket for said standard carried by said casing in which the rod is movably mounted, andmeans carried by the casing for shifting the outer end of the rod in all directions.

2. A focusing mechanism for projecting lamps, comprising a rod arranged longitudinally of the lamp, a standard carried by and substantially at right angles to the rod, said standard being mounted in. front of the mirror, a socket for the light source carried by the standard substantially in the optical axis of the lamp, a guide for the standard in which the rod is slidably and pivotally supported, and means for universally adjusting the rod with respect to the guide.

3. The combination with a light projecting mirror of a socket for a light source arranged substantially in the optical axis of the mirror, a standard substantially at right angles to the socket and'on which the latter is carried, a rod substantially at right angles to the standard and on which the latter is carried, such rod extending to one side of thesocket and mirror, means supporting the end of the rod forward of the mirror for sliding and universal pivotal movement, a plate in which the rod is carried adjacent its rear end, means cooperating with the plate for imparting longitudinal movement to the rod, such plate being movable substantially in its own plane I to impart upward, downward, and sidewise movement to the rod.

4. The combination with a light projector of a socket for the light source arranged substantially in the optical axis of the projector, a standard substantially at right angles to and supporting the socket, a rod ofl-set from and substantially parallel to the socket and on which the standard is mounted, means supporting one end of the rod for sliding and universal pivotal movement but preventing rotary'movement of such rod, and means by which the other end of the rod canbe adjusted in'any direction.

5. In a projector, the combination of a reflector, a socket for the light source arranged substantially in the optical axis of the reflector, a single rod offset from and substantially parallel to the optical axis of the reflec tor, a standard supported by the rod and carrying the socket, means supporting the end of the rod adjacent the standard for sliding and universal pivotal-movement and preventing rotary movement of such rod, and means supporting the opposite end of the rod for universal movement.

In testimony whereof I hereunto aflix my signature.

- STATES LEE LEBBY. 

